But he added: "Unfortunately, concessions and at times supportive actions for brutal terrorists indicate a double standard by the Western world in dealing with terrorism, and have made terrorists bolder."

Iran has repeatedly accused Western governments of directly or indirectly supporting jihadists through their backing for rebels fighting to overthrow Syrian President Bashar al-Assad.

Shiite-majority Iran strongly supports Assad against Sunni jihadists such as the Islamic State group, which claimed responsibility for Thursday's attack.

It labels all rebels fighting against Assad's forces as "terrorists."

"Once again we reiterate that terrorism is the first and most urgent danger for peace, stability and global security," Ghasemi said.